U.S. Embassy Supports WWF Efforts to Track the Mekong Giant Catfish

Vientiane, Laos – WWF, with an environmental grant from the U.S. Embassy, is undertaking a new study to determine the viability of tagging and satellite tracking the enigmatic and iconic Mekong giant catfish, and other migratory species found in the Mekong River.

While the Mekong giant catfish can reach three metres in length and weigh up to 350kg, very little is known about this river titan. It is hoped a successful tagging programme will reveal how far this long distance swimmer travels during its migration, and what it consumes to reach such massive proportions.

“While very little is known about the movements of the Mekong giant catfish, what is known is that their future is uncertain.” said Dr Victor Cowling, Landscape Manager with WWF-Laos “If we can learn more about the habits and behavior of the catfish, we stand a better chance of protecting this endangered species, and the river it inhabits.”

The WWF feasibility study, funded by the U.S. Embassy and carried out during a 6 month period, will determine whether pop-up satellite archival tags (PSATs) can be used to track Mekong giant catfish. For this study other large migratory species of catfish will be tagged. PSATs are mainly used to track the movements of large, migratory marine animals, and have never before been used in rivers.

A PSAT is equipped with a means to transmit data via satellite. Though the data is physically stored on the PSAT, its major advantage is that it does not have to be physically retrieved for the data to be available. Location, depth, and temperature data held in the PSAT can be used to answer questions about migratory patterns, seasonal feeding movements and daily habits.

“Current scientific information suggests the Mekong giant catfish migrate from the Tonle Sap Lake in Cambodia up the Mekong River to spawn in northern Thailand and Laos,” added Dr Cowling. “If the study shows that this technology has the potential to successfully track these river giants, we hope to strengthen scientific knowledge of this elusive species and reveal its secrets.”

Four out of the world’s top ten giant freshwater fish species can be found in the Mekong River which flows through Cambodia, China, Lao PDR, Myanmar, Thailand and Vietnam. More giants inhabit this mighty river than any other on Earth.

A century ago the Mekong giant catfish was found to inhabit the entire length of the river from Vietnam to southern China. Today, the population is in decline with scientists estimating that numbers have plummeted by 90 per cent in just two decades. A combination of infrastructure development, habitat destruction and overharvesting is quickly eroding populations of this extraordinary species.

“Without the ability to move up and down rivers, the fish have fewer opportunities to breed,” added Dr Cowling. “Currently, the lower Mekong remains free-flowing, which presents a rare opportunity for the conservation of these species. But the clock is ticking.”

The results of the WWF feasibility study will be available in September 2012. If PSATs are shown to be successful in tracking the Mekong giant Catfish, it is hoped a tagging programme can be established in 2013.